Drilling tool



'E. G. BOICE DRILLING TOOL June '12, 1956 I 3 Sheets-Sheet 1 Filed June 2, 1952 E/v/n 6. 50/09 INVENTOR.

J n 2, 1956 E. s. BOICE 2,750,154

DRILL-INC TOOL Filed June 2, 1952 3 Sheets-Shes,"v 3

5/1/07 6. Home 23 INVENTOR.

M;M 43.7 rank.

,4 TTOR/VISYJ United States Patent DRILLING TOOL Elvin G. Boice, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application June 2, 1952, Serial No. 291,182

1 Claim. (Cl. 255-4) This invention relates generally to new and useful improvements for drilling tools, and more particularly to fluid valving means for impact drilling tools.

It is an object of this invention to utilize the flushing fluid as a means of furnishing motive power to actuate the drilling tool.

Another object is to obtain a relatively compact and economical drilling tool which may be connected to the end of a standard well drilling string;

Another object is to provide a drilling tool which will deliver a relatively high number of impact blows per minute to assist the drilling of bore holes.

A further object is to provide an impact drilling tool which may be used with a standard drill bit.

One of the specific objects of the invention is to provide a new and improved impacting device which may be combined with a conventional rotary type well drill and which will initially utilize the energy of the drilling fluid passing therethrough to put itself in operating motion, and then utilize such energy to deliver the desired impact forces.

Other objects and advantages will appear from. the following description and accompanying drawings wherein a preferred form of the invention is disclosed.

In the drawings:

Fig. 1 is a view partly in elevation and partly in section showing the drilling tool.

Fig. 2 is a sectional view taken through the turbine and valve of the tool.

Fig. 2A is a view partly in elevation and partly in section showing the cams.

Fig. 3 is a transverse section taken on the line 3-3 of Fig. 2.

Fig. 4 is a transverse section taken on the line 44 of Fig. 2.

Fig. 5 is a transverse section taken on line 5--5 of Fig. 2A.

Fig. 6 is a sectional view taken through the turbine and valve.

Fig. 7 is an isometric view showing a modified form of the valve member.

In Fig. l the drilling tool 1 is shown connected to the lower end of the drill string 2. Connected to the lower end of the drilling tool 1 is a drill bit 3 which is shown engaging the bottom of the bore hole 4.

As shown in Figs. 2, 2A, 3 and 4 the drilling tool 1 comprises a cylindrical body 5; an upper connector 6 which is adapted to be screwed into the lower end of the drill string 2; and a lower connector, or anvil, 7 which is threaded to receive a drill bit 3. Within the cylindrical body 5 is an inner element 8 which is adapted to rotate and reciprocate within the-cylindrical body 5. Attached to the upper end of the inner element 8 is a turbine bucket assembly 9 which may be attached to the inner element 8 by means of welding as shown at 10. At the lower end of the inner element 8 a cam 11 is provided which cooperates with a cam 12, on the upper end of the lower connector 7, to cause the inner ice element 8 to rise and fall upon rotation thereof. The cylindrical body 5 may be attached to the upper connector 6 by means of a weld 13 and to the lower connector 7 by means of a weld 14, or other suitable means. The upper connector 6 is provided with a central bore 15 which communicates with the flushing fluid passageway (not shown) in the drill string 2. Communicating with the bore 15 are fluid passageways 16 which extend downwardly and outwardly and discharge flushing fluid into the collection chamber 17. A turbine nozzle 18', which is an extension of the upper connector 6, fits within the body 5 and over the turbine bucket assembly 9.

A seal ring 19 is provided between the turbine nozzle 18 and the inner wall of the body 5 to seal the space therebetween. Slots 20 are provided in the turbine nozzle 18 and are adapted to direct the flushing fluid to impinge the buckets 21 of the turbine bucket assembly 9. A central bore 22 extends through the turbine bucket assembly 9 and communicates directly with the longitudinal fluid passageway 23 of the inner element 8. A space 24 is provided so that the inner element 8 may 'rise and fall as it rotates upon the cams 1-1 and 12. A transverse opening 25 intersects passageway 23 of the'in'ner element 8. Disposed slidably in opening 25 is a valve member 26 which has enlarged ends 27 and 28 and a reduced central, cylindrical portion 29. Valve end 28 is counterbored as indicated at 39 to reduce the weight thereof. A spring 31, which is attached to the valve member 26 and the inner element '8, serves to urge the valve member 26 into the position shown in Fig. 2. A guide pin 32 prevents the valve member 26 from turning about its axis.

Fig. 6 shows a modified valve member 26a in which is provided a central passageway 33 topermit the passage of flushing fluid therethrough and through passageway 23 of the inner element 8.

Fig. 7 shows, as a further modification, a valve member 26b wherein the reduced central portion is a web 34.

Valve members 26, 26a and 26b operate in the same manner in that one end of each of said valve members is heavier than the other end and the central portions of each, when in the position shown in Fig. 2, permit the passage of a relatively large volume of fluid through the passageway 23 of the inner element 8.

Roller bearings 35 (Figs. 1, 2 and 2A) are mounted in raceways 36 of the inner element 8' between said element and the body 5, to facilitate rotation of the said inner element. 7

Operation of the drilling tool is as follows: the drilling tool 1 is attached to the drill string 2 (Fig. 1) and "the drill bit 3 is attached to the lower end of the drilling tool. The entire apparatus is lowered into the bore hole and conventional pumps (not shown) are operated to force flushing fluid through the drill string 2 to the drilling tool 1. The fluid passes through the upper connector bore 15 (Fig. 2); through the passageways 16; into chamber 17; and through slots 29 to impinge upon the turbine buckets 21 of the turbine bucket assembly 9, causing the inner element 8 to rotate relative to the body 5. Cams 11 and 12 then cause the element 8 to rise and fall thereby impacting the lower connector 7. These impact forces are transmitted through the connector 7 and through the drill bit 3 to the formation at the bottom of the bore hole 4 (Fig. 1). When the drill string 2 is rotated to cause the bit 3 to penetrate the formation, the impact forces applied by the tool above described facilitate the drilling of the formation by the drill bit. The flushing fluid, after passing through the turbine bucket assembly 9 (Fig. 2), enters the longitudinal passageway 23 of the inner element 8 and passes by the valve member 26; through the passageway 39 (Fig. 2A) of the lower connector 7; and through passageway 37 of the drill bit 3. Referring to Fig. 1, the fluid emerging from the bottom of the bit 3 passes upwardly in the annular space 38 between the drilling tool 1 and the wall of the bore hole.

Since the fluid passing through the tool must initially exert a strong torque to start rotating the inner element 8, the valve member 26, as shown in Fig. 2, will initially permit a relatively large volume of flushing fluid to pass through the bore 23 of the element 8 until the element 8 has gained suflicient revolutions per minute to reduce the torque requirements for rotating the element 8. As the inner element 8, in which is disposed the valve member 26, gains suflicient rotational speed, the centrifugal force exerted upon the valve will overcome the resistance of the spring and move the valve to restrict the flow of the fluid through the tool. The valve 26 will be moved in a radial direction to the left in Figs. 2 and 4. Fig. 6 shows valve 26a after it has been moved by the centrifugal force to restrict the flow of the fluid, and, as shown by Fig. 4, the valve 26 moves from the solid line initial position to the dotted line position to obstruct partially the passageway 23. Since the enlarged valve end 27 is heavier than the other valve end 28, the valve member 26 is centrifugally influenced to move as above stated upon rotation of the inner element 8. The enlarged end portion 28 of the valve 26 is thereby moved into the passageway 23 of the element 8 to obstruct same partially and thereby restrict the flow of fluid therethrough resulting in greater downward pressure acting on the element 8 thereby resulting in greater impact forces being delivered to the drill bit 3. The valve member 26 thus serves as a governor since the rotational speed of the inner element 8 is limited, as the passageway 23 is restricted, and as a correspondingly greater downward force is applied to the element 8. The spring 31 yieldably holds the valve member 26 in the position shown in Fig. 2 until the bias of the spring is overcome by the centrifugal influence of the valve member 26 as it is rotated with element 8.

Thus it will be appreciated that the valve member 26 serves the important purposes of initially permitting a large volume of flushing fluid to pass through the drilling tool 1 until the inner element 8 is started and gains rotational speed; and thereafter also serving to limit the rotational speed of the inner element 8 by restricting the fluid flow through the passageway 23 and by presenting a greater area for the flushing fluid to act upon. These valve functions are preformed automatically and in accordance with the demand of the drilling tool.

In the preferred embodiment, the cylindrical body is shown as welded both to the upper connector 6 and to the lower connector 7. In the drilling of deep oil wells, it is customary to cause a portion of the drill string weight to be imposed upon the drill bit 3 so that the formation may readily be drilled by rotation of the drill string. As the weight is imposed upon the drill bit 3, the cylindrical body 5 is put in compression; accordingly, impact blows delivered to the lower connector 7 will be transmitted through the drill bit 3 to the bottom of thebore hole 4. In other words, the bit 3 is pressed against the bottom of the bore hole 4 by the weight of the drill string transmitted through the cylindrical body 5 and the lower connector 7 so that When the element 8 imparts downward impact blows to the lower connector 7, these impact blows are transmitted through the bit 3 upon the bottom of the bore hole 4.

It is contemplated that the rotation of the inner element 8 will be effected before the drill string 2 is rotated for drilling and it is preferred that the said inner element rotate in a direction opposite to the direction of rotation of the said drill string so that the number of impact blows per minute will be increased.

The invention is not limited to the preferred embodiment herein disclosed. Various changes within the scope of the following claim will be apparent to those skilled in the art.

I claim:

A well impact drilling tool comprising an upper connector having a passageway longitudinally thereof adapted to be attached to a downwardly depending drill stern, a hollow tubular cylindrical body extending downwardly from said upper connector and secured to and carrying at its lower portion a lower connector having a longitudinal passageway therethrough communicating with the bottom of a Well bore and communicating with the longitudinal passageway in said upper connector, said lower connector being adapted to receive a Well drill, the upper end wall portion of said lower connector constituting a cammed anvil surface, an inner element disposed within said cylindrical body and having a longitudinal passageway therethrough in communication with the passageways of said upper and lower connectors and adapted to rotate in and reciprocate longitudinally with respect to said hollow tubular body and above the anvil surface of said lower connector, a fluid actuated turbine supported by its stator by said upper connector and having an axially movable rotor detachably secured to the upper portion of said inner element whereby said inner element is rotated by said turbine rotor when fluid is introduced thereto through the passageway in said upper connector, the exhaust fluid from said turbine passing into the passageway of said inner element, the lower end wall portion of said inner element constituting a cammed hammer surface to match the cammed anvil surface of said lower connector, said inner element being provided with a transverse passageway intersecting the inner element longitudinal passageway in a region below said turbine and at a substantial distance above said cammed hammer surface, a slidable valve in said transverse passageway having enlarged end portions one of which is heavier than the other and spaced from each other by a reduced central portion, the lighter of said enlarged end portions being secured to said inner element by a spring member to bias said valve so that the central portion thereof is in alignment with the longitudinal passageway in said inner element thereby permitting initially a large volume of fluid to pass through said turbine and to said well drill until said inner element is rotated by said turbine and gains rotational speed, said valve when moved by centrifugal force exerted upon the heavier end portion thereof due to the increased rotational speed of said inner element serving to limit the rotational speed of said inner element by restricting the flow of exhaust fluid from said turbine due to a restriction of the longitudinal passageway in said inner element by said lighter enlarged end portion moving against the resistance of said spring member thereby resulting in a greater downward fluid pressure acting upon said inner element whereby the hammer surface of said inner element will be caused to deliver greater impact forces to the anvil surface of said lower connector and to said well drill.

References Cited in the file of this patent UNITED STATES PATENTS 1,329,515 Egger Feb. 3, 1920 2,287,157 Wolff June 23, 1942 2,371,248 McNamara Mar. 13, 1945 2,529,349 Nathan Nov. 7, 1950 

